Basic jQuery SHOW (if/else) almost working, syntax help

Basic jQuery SHOW (if/else) almost working, syntax help

OVERVIEW
Prototyping a page for client, who wants validation on a specific select option. Wants this validation to occur on submit of page.
I am using jQuery SHOW function if select option specific index = true, If index = false, then go to some other page.
The SHOW function works on the IF portion (desired option value = true)
But then immediately fires the ELSE portion (go to some other page)

HEAD
<script language="javascript" type="text/javascript">
   $(document).ready(function() {
      //validate if select option = other
      $("a#btn_update").click(function() {
         if (document.myform.myselect.options[4].selected == true) {
         $("div#error_wrap").show("slow");
          };
         else (document.myform.myselect.options[4].selected == false); {
         window.location.href = "http://www.google.com";}
return true;   
         
   });         
   });         
</script>


HTML
<div>
   <ul>
      <li>Reason:</li>
      <li>
      <form action="#" method="post" name="myform">
      <select name="myselect" id="myselect">
         <option value="0">Select...</option>
         <option value="1">Reason 1</option>
         <option value="2">Reason 1</option>
         <option value="3">Reason 1</option>
         <option value="4">Other</option>
      </select>
      </form>
      </li>
   </ul>
</div>